The profiles of human bodies are versatile and it is difficult to select a suitable undergarment or accessory for each individual. Sometimes, non-fitting garments or accessories may cause discomfort and even allergy to the individual due to inappropriate pressure exerted on their body. This problem becomes worse if the wearer participates in intense exercise. For example, conventional socks are usually made of elastic fibers or other synthetic fibers or a blend of the both. The sock top is normally made of elastic fibers or threads to increase the elasticity so that the sock does not easily to slide down the leg. However, the increased pressure exerted by the elastic fibers/threads on the leg is very uncomfortable. Secondly, the high-pressure may cause indentation marks on the skin of the leg after prolonged wearing. It has been found that the indentation by the socks can block blood circulation and therefore has a potential to be very harmful. Another example is waistbands that are normally made of elastic strips. After eating or after long distance traveling, the wearer will feel discomfort because the tightness of the waistbands increases significantly after the eating or prolonged travelling.
Pressure garments have been used to cure wounds and treat vascular problems. Pressure garments for healing wounds can reduce the effect of scaring whereas pressure garments for varicose veins are more effective in treating venous disorders than when no compression is applied. However, these pressure garments are made of conventional textiles and have problems during use. Firstly, a pressure garment especially a high-pressure cure garment type is so tight that they are difficult to wear. Secondly, traditional pressure garments have the tendency of loosening after wearing several times.
Shapes of garments and accessories made of traditional fabric after the garments and accessories are made cannot be changed into other shapes or styles. Although garments made from spandex fibers can be deformed to any shapes, the deformed shape cannot be fixed for aesthetic design because the spandex fibers shrink to the original length immediately when the external force is released.
Shape memory metallic alloy wires can be used in woven fabric for aesthetic design. The garments and accessories made of shape memory metallic alloys can change their shapes with varying environmental and human body temperature. However, there are many problems associated with the intrinsic properties of metallic alloy. Firstly, due to the significant differences of mechanical and surface properties of shape memory metallic alloy wires and traditional fabrics, shape memory metallic alloy wires have a tendency to protrude out of the fabric. Complicated structures of fabric with shape memory metallic alloy wires are difficult to accomplish. Secondly, due to the low extensibility and high stiffness of shape memory metallic alloy wires, knitting of shape memory metallic alloy wires is not easy to perform. If the structure of shape memory fabric with shape memory metallic alloy wires is not designed properly it will significantly affect the soft handling of the fabric.
Smart functional textiles are developing rapidly. Textiles with novel functions such as luminescent textiles, textiles display, emotion sensing dress, and self-cleaning textiles have been developed. However, significant developments in smart garments and accessories with shape memory functions are few.